Final answer:
The resting state of Bradley's motor neurons indicates a high concentration of sodium ions outside and potassium ions inside the neuron, with sodium-potassium pumps maintaining this balance. Thus, sodium ions are concentrated outside the neurons and chloride ions are concentrated inside the neurons.
Step-by-step explanation:
When Bradley's motor neurons are in a state where his muscles are not moving at all, and he is deeply relaxed, this typically indicates that the motor neurons are in a resting state. During the resting state, the resting membrane potential is established by the distribution of ions across the neuron's plasma membrane. Specifically, sodium ions (Na+) are at a higher concentration outside the neuron, while potassium ions (K+) are more concentrated inside the neuron. Additionally, chloride ions (Cl-) are typically found in higher concentrations outside the neuron. This ion distribution is primarily maintained by the sodium-potassium pump which uses ATP to actively transport three sodium ions out of the neuron for every two potassium ions pumped in, resulting in the inside of the cell being negatively charged compared to the outside.
Therefore, the correct answer to the question is that sodium ions are concentrated outside the neurons and chloride ions are concentrated inside the neurons. This choice best reflects the resting state of a neuron as described by the information provided.